> On Mon, Jan 12, 2009 at 9:52 PM, Ingo Molnar <mingo@elte.hu> wrote:> > The reason why we wanted to re-test the functional changes was that> > Torsten's crash looks very weird: double Call Trace line, a crash in the> > scsi/ata code, showing the after-effects of some sort of memory corruption> > there.> > The double Call Trace: line was a copy&paste error on my part. Its not> there in the original oops.> > Sorry for that...

ah, ok - that's fine.

I was just wondering whether it was two CPUs crashing at once and producing an overlap - or something like that. (although typically in that case we dont get such nice line duplication - we get totally garbled output of the two oopses superimposed.)

It's just that when an oops looks weird we have to look at every small detail, to be able to imagine the unimaginable.

Bugs you cannot even imagine are the toughest nuts usually, as the process of debugging narrows imagination usually - often it involves repetitive automatisms which are not helpful in expanding your thoughts to cover tricky, unusual bugs.

If an oops looks difficult there's a way out of that trap: co-debug in duos if you can - the same folks rarely get unimaginative for the very same detail. (Or put it aside and leave it for the next morning - to flush out the invisible temporary mental dead-ends one has installed subconsciously and which are blocking you from reaching the real solution.)